salted paper and photogenic drawing

**Warning: this blog is currently suffering from formatting issues and is not nearly as pretty as it could be.  Please disregard it as best as possible.

Salted Paper Print: 

http://www.nga.gov/podcasts/fullscreen/0803arttalk02.shtm

Introduction:

A photogenic drawing is an image applied to paper by the use of contact on a photosensitive surface. It is primarily a sort of silhouette, though the density of the object applied can alter the outcome, for example a leaf pressed against photosensitive paper and exposed to sunlight can let some UV rays through the thinner portions of the leaves but not the veins as they are denser allowing the veins to show up within the leaf image as an end result when typically, or in theory, should everything have the same density and no other light rays get through all the images would be simple silhouettes.

The way in which the light hits the paper is also important. The darkest exposure will be through direct sunlight, but as light bounces off of items, sunlight that has hit an object can affect the outcome of the image as well, leading to lighter or even darker spaces (should more light be directed to one area) on the final image for an object that isn't pressed completely flat to the paper. It is important to be aware of how light can bend because should you use glass plates over your objects to hold down them down during exposure and must make due with, say, multiple sheets or the corner of glass might cut across the paper in some manner, while you might think that since it is clear it will do nothing, you will find that a line can develop since the light will enter through the glass and bend at the corner, thus altering the density of light in that area and leaving a visible line. 
The images are warm in tone because they use sunlight to develop called printing out.  Because the sun develops the image and not chemicals in a dark space, the warmth is evident in the photos.  When the image is fixed with hypo, the image is lighter because the silver is removed.  But when the image is fixed with salt, the silver is not removed and no bleaching occurs.  This keeps the picture dark, and can potentially lead to further darkening if exposed to sun as the salt doesn't guarantee the silver from not reacting and further darkening

floating paper in salt solution

Salted paper is a photosensitive paper in which salt is applied to a page and then silver nitrate is brushed over top of that (with drying in between). The dry salt reacts with the silver applied in the top coat (two coats worked best in experimentation – see blog post: photogenic drawing for data on best concentrations, coats and paper for experimentation) and produces silver chloride which is a photosensitive compound insoluble in water. When exposed to light, particularly sunlight, though results can be achieved with very little sunlight and thick cloud cover - the exposure is will longer, the silver will darken and anything blocking light from the paper will leave an image. However, without fixing, the image will not last as once the object is removed the light will activate and darken the remaining silver compound on the page until the entire thing is dark and no more image exists. To prevent the further reaction of sunlight and silver, the image can be fixed onto the page through two methods. Soaking the images in salt saturated solutions will apply more salt to the page and while it does not effectively remove the reactant silver it will make it harder for the silver to react through the excess salt.

The other method of fixing an image, a better method and more popular, is the use of hypo. Hypo is sodium thiosulfate. It works by removing undeveloped silver chloride crystals from the paper and thus preventing the image from darkening into obscurity. However, it will lighten or bleach the images greatly and a lengthy exposure time is suggested in order to retain a darker image after the hypo bath regardless with how quickly the image may darken once exposed to the sun.

Historical Background –

Talbot's Camera Obscura Replica 1820 (2)

Photogenic drawings were developed by William Henry Fox Talbot, a gentleman scientist. He announced the results of his experiments in 1839. The images created are silhouettes or negatives and his solution to fix the images consisted of the above mentioned salt bath. John Herschel picked up Talbot's experiments and discovered the fixing method of hypo.  Talbot used camera obscuras to create tiny images. Further information on Talbot and Herschel can found:












Talbot: http://www.rleggat.com/photohistory/history/talbot.htm

Herschel: http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Herschel.html


 
Process:

The basic procedure for creating salted paper is to immerse or coat a page of good quality paper on which an image is desired, and then dry it. After a coat of silver will be applied though historical documents change the approximate concentration of salt and silver solutions, and some other specifics as the people of the 18^th century were experimenting with finding the best methods, as we did in a previous lab [see photogenic drawing experiment for details]. See 'Our Experiment' below for the process we utilized.

Salted paper and photogenic drawing were one of the first real ways of capturing images in a relatively short period of (exposure) time. It became a rather popular method with its simplicity in creation opposed to the Daguerreotype that used a relatively complicated method with harsh chemicals [ more information (a quick introduction) on Daguerreotypes can be found: http://en.wikipedia.org/wiki/Daguerreotype]. Several publications of the 19^th century deal with the photographic process of salted paper and the application to make photosensitive papers for images, as well as hypo fixing methods. One such publication is:

http://books.google.com/books?id=j2USAAAAYAAJ&pg=PA139&dq=salted+paper+photogenic+drawing&hl=en&ei=_KmrTdueIeGG0QHb_b35CA&sa=X&oi=book_result&ct=result&resnum=2&ved=0CEYQ6AEwAQ#v=onepage&q=salted%20paper%20photogenic%20drawing&f=false

It mentions soaking the paper in a salt solution and then pressing it with a wooden press to keep it flat and smooth. The objective is to keep the paper on which the image will be printed clean and pretty to look at. This is different than what was suggested for our lab procedure where the surface of the paper was brushed with salt solution. We had also taped it to the surface in an attempt to keep it from bubbling up aggressively and then curling during drying. The bubbled paper texture still occurs with the wetting of the paper, but is not as severe as if it was left untapped.

Another publication, Light: An examination of all the phenomena connected … by Robert Hunt, mentioned a manner in which the sensitivity of the paper can be maximized if a paper was made, salted and silver applied, and then kept for several weeks. Through the reapplication of silver to the surface "it becomes sensible to Light, even more than it was at first." http://books.google.com/books?id=GqoaAAAAYAAJ&printsec=frontcover&dq=Light:+An+examination+by+Hunt&hl=en&ei=SrOrTemAMMWtgQedg9jzBQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CEAQ6AEwAA#v=onepage&q&f=false


Our Experiment:

Silver to be applied to papers

Drying between coats

For the purposes of our lab, our group used salt and silver solutions of 2% and 12%, respectively, with two coats of silver and no additional salt coat in between. The paper was dried between each coat. First, salt was applied with a pipette and then spread over the paper with a sponge brush. A hair dryer was used to dry in between coats on a low setting. A coat of silver was applied as smoothly as possible, else poor sensitivity will develop on the page leading to poor images or a ghosting effect. After using a hair dryer once more to dry the paper, another coat of silver was applied to the page. The page will be covered with a silver compound that is insoluble to water called silver chloride. Crystals of this compound bond on the surface of the paper. The density of these crystal formations are affected by the concentration of silver and salt in each area. If the salt or silver is not applied smoothly over the surface of the paper, then ill effects can occur. The dual coats of silver tend to limit the possibility of a poor image.

We did not experiment in alternating salt coats as mentioned in the above reading though it may be interesting to try in the future.

It is important that once the paper is sensitized with silver that the light exposure is limited until the actual exposure is desired. The paper will steadily darken in limited light so it is best to exposed the papers as desired as soon as possible, particularly when a dark room is ill equipped as a darkroom (i.e. light sneaking in around the edges of blinds as in our classroom).

For the sake of our experimentation, we desired to test the effect of colored filters on the image. Three filters were cut from cellophane in the colors: yellow, red, and blue. It was our belief that the colored filters will affect the overall image. In order to test the effect of no filter on the page and for a little artistic expression, we cut stars into the centers of the cellophane and then applied them, with tape over three individual squares of sensitized paper. The stars cut out of the center, however, were not flattened to the surface of the paper and created difficulties later in the exposure. Glass should have been applied to the surface to keep the corners within the star from sticking up and thus letting light slip underneath the filter.

Our objects: filters, wood cut flower, false flowers, etc

Four other photogenic drawings were made using items brought from home. Potpourri, false flowers (not plastic but sort of thick, structured fabric), and a flower wood cut out used as objects for our drawings. These were primarily done for fun, in my opinion, and the results were quite pleasing and exciting. Glass was used over top the objects to prevent them from blowing away. Four sheets of glass were placed over top, creating the above mentioned lines after the fact.

On two large cutting boards, we taped three papers for the filter test and then four papers on the other for our drawings. Salt and silver were then applied to the papers. Tape on all four sides of our squares kept the bubbling to a minimum. Once dry, we applied our above mentioned objects and filters to the papers and planned for exposure. Glass was only used on the object images, not the filter images.

Filtered Experiment Exposure

Objects exposed to sun with glass over top

Still attached to their boards, we took the images out into the sun. It was a sunny day, though a bit of wind blew around campus. The images began to change and darken within thirty seconds of exposure. For the sake of a dark image that would not bleach out as badly when put through the hypo baths, we exposed our images for three minutes. When going out with the star filters, the way the sun came down affected the images as we turned them from when we went down the steps when first going outside to when we put them in their final resting place for the duration of the exposure time. Therefore, light snuck underneath the filters on two sides, altering the way the stars came out over all (though admittedly they were not the best star cut outs, just something done quickly).

The objects images developed as quickly as the filters. These two boards were taken out a different times, though one followed shortly after the other. A breeze got underneath the glass and moved an petal of potpourri from one image to another close by. The result was interesting as the place where it had been turned a bit ghostly, while the final resting place didn't darken as darkly as the rest of the image background, giving a sort of ghostly look, but hardly noticeable unless you were looking for it. It was particularly bleached out after the hypo bath, further making it less noticeable.


 
Observations/Experience:

The images came out quite dark, even after the fixing bath. The overall result was exciting to see everything working so quickly – our first experiments with contact printing being anthotypes is quite slow and not nearly as exciting for college students of the 21^st century. The dark backgrounds and the lighter object images were negatives. The false flowers were not completely opaque to the sun's rays and thus darkened a decent amount underneath the objects. It left a gray image underneath. The result had some depth to the images I didn't expect.

Object Images after exposure, before hypo bath

The woodcut flower had some depth to it as well. The way the sun hit the corners of the object shadowed some of the space within and thus limited the exposure to the sun's rays, making it not as dark. It looked more like the flat cut out than I expected, as I had just expected the overall flat image without depth.

blue filter after exposure

red filter after exposure

yellow filter after exposure

The filters were interesting to see and I had little idea on what the overall result might be. The blue turned out to make the darkest image, turning so dark that the star was not visible at all after the exposure (before the hypo bath). Yellow and Red filters had similar results, leaving faded, not very dark images. 

red filter photo after hypo

yellow filter photo after hypo

blue filter photo after hypo

The hypo bath lightened the pictures a lot. At first, we thought the images were lost, but with the hypo bath (this was the first time we used hypo for fixing) the solution bleached the images, revealing the stars on the filter experiments as well as making the false flower images to be more visible.
In our excitement with our lab and actually creating images that were quite clear, we used the rest of our lab time to make more papers and exposed them, though some of us took some home to attempt images with camera obscura. There are no results of these additional experimentation, but it is something quite fun to do. Time constraints, however, limit the number of tests or fooling around that we could do. It is only a two hour class.

Before Hypo Bath.  See depth along bottom edge.

It is important to remember that silver cannot be put down the drain in clean up. So any silver nitrate experimentation performed should be kept in containers and exposed of properly. This includes the silver concentrations, and hypo solutions that remove silver to keep from over exposing. The water used for rinsing the images is not something that has to be kept as the silver chloride is insoluble and will not wash away down the drain.

After Hypo Fixing

The hypo bath was arranged as four stations. Three minutes spent on each bath was necessary. The papers are immersed in a water rinse, then a hypo bath and then another hypo bath, ending in another water rinse. An hour of rinsing is required to remove any excess hypo from the images. This was performed at home as there was no more time in class. Keeping the images damp, we took them home to perform the final rinse. The hypo solution was a ten percent concentration made up by the instructor and the student assistant as the class went about their lab, making photosensitive papers and then exposing them.

Additional Information on Salted Paper and Photogenic Drawings can be found:

On Processes: http://www.alternativephotography.com/wp/processes/saltprints/a-dash-of-salt

On Processes: http://unblinkingeye.com/Articles/Salt/salt.html

Images in the Library of Congress: http://www.loc.gov/pictures/related/?fi=format&q=Salted%20paper%20prints--1850-1860.

Some History: http://albumen.conservation-us.org/library/monographs/reilly/chap3.html

Modern Day Salted Paper Artist: http://www.artlimited.net/image/en/278520

Summary:

Making salted paper is easy and relatively quick to do, allowing for easy fun. The silver is something to be careful with, however, as it can burn your skin. When working with silver nitrate, it is important to wear a lab coat to protect your clothes and skin, to wear gloves to protect your hands, and to wear goggles to protect your eyes. Not doing so is sort of foolish and not really something that is so hard to do that is avoided. It is best to only make the paper to be used to avoid any unwanted exposure beforehand in our situation, as the room we work in is not the darkest of rooms. Playing around with different types of translucent objects, perhaps color glass, and some objects that are thinner or thicker in density would be fun to do should there be more time. Should the opportunity to play around with process arise again, it would be interesting to experiment with digital negatives and creating what would be considered a photograph of these days, actual images of rooms, or something with a camera obscura, of even portraits in some manner. The color glass would be a particular interesting activity as it would bring into effect the filter papers that we experimented with. Different colors lead to different effects on the light filtering through to the paper and provides an interesting result.  A collage of glass and other objects might be something interesting, as well as the removal of objects and replacement with a new object to further play with the ghosting effect.


 
Image References:

1 - http://www.precinemahistory.net/images/talbot_oval.gif

2 - http://www.ssplprints.com/lowres/43/main/19/98554.jpg